Numerical simulations of conical fluidized bed combustors were carried out to estimate the effect of collision elasticity, parameterized by the particle-to-particle and particle-to-wall coefficients of restitution, upon the combustor's hydrodynamics and heat transfer. The Eulerian-Eulerian two-fluid model was used to simulate the hydrodynamics and heat transfer in the combustor, and solid phase properties were calculated by applying the kinetic theory of granular flow (KTGF). Sand of size 560 mu m was used as a bed material and air was used as a fluidized gas, introduced at the velocity of 3 m/s at the combustor inlet. In the simulations, increasing the particle-to-particle restitution coefficient increased the bed pressure drop and caused significant changes to other hydrodynamics parameters. Oppositely increasing the particle-to-wall coefficient of restitution decreased the bed pressure drop. Changes to either the coefficients studied had little effect on heat transfer. (C) 2015 Elsevier Ltd. All rights reserved.